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Biomedical subjects

A Massone

Publications and source records attributed to A Massone.

At least 19 recordsLinked to original sources

Feline poxvirus infection. A case report.

Poxvirus infection of a domestic cat is reported. The clinical signs consisted of skin lesions only, which healed within two and a half months. Histopathology revealed cytoplasmatic inclusion bodies typical of pox virus infection. Virus particles morphologically related to the genus orthopoxvirus were detectable in the embedded skin tissue and in skin scraping by electron microscopy. No specific lesions were observed in the chick embryo chorioallantoic membrane inoculated with an extraction from skin scabs of the cat.

Animals↗

Heterogeneous localization of epitopes along axonemes of mammalian cilia.

The specificity of four monoclonal antibodies, raised against mammalian ciliary axonemes, was determined by both immunofluorescence and immunoblot experiments. Three antibodies reacted with epitopes which are differentially located along axonemal length. Among these, antibody 3.12 recognized an epitope common to different dynein heavy chains, reacted only with tracheal cilia and specifically stained the proximal portion of the ciliary axoneme.

Animals↗

Molecular characterization of the 128-kDa immunodominant antigen of Helicobacter pylori associated with cytotoxicity and duodenal ulcer.

Helicobacter pylori has been associated with gastritis, peptic ulcer, and gastric adenocarcinoma. We report the nucleotide sequence and expression of an immunodominant antigen of H. pylori and the immune response to the antigen during disease. The antigen, named CagA (cytotoxin-associated gene A), is a hydrophilic, surface-exposed protein of 128 kDa produced by most clinical isolates. The size of the cagA gene and its protein varies in different strains by a mechanism that involves duplication of regions within the gene. Clinical isolates that do not produce the antigen do not have the gene and are unable to produce an active vacuolating cytotoxin. An ELISA to detect the immune response against a recombinant fragment of this protein detects 75.3% of patients with gastroduodenal diseases and 100% of patients with duodenal ulcer (P < 0.0005), suggesting that only bacteria harboring this protein are associated with disease.

Amino Acid Sequence↗

The Hsp60 protein of Helicobacter pylori: structure and immune response in patients with gastroduodenal diseases.

Helicobacter pylori is a human pathogen that has been associated with gastritis, peptic ulcer and gastric carcinoma. The role of the direct action of H. pylori virulence factors and of the induction of autoreactive immunity in the development of chronic gastritis has not been clarified yet. Here we report the cloning and molecular characterization of a gene of H. pylori coding for a protein of 58 kDa, recognized by sera of patients affected by H. pylori-induced gastroduodenal diseases. This antigen is present in all the H. pylori strains tested and it belongs to the Hsp60 family of heat-shock proteins, with high homology with other bacterial and eukaryotic proteins of the same family. This class of homologous proteins has been implicated in the induction of autoimmune disorders in different systems. The presence in infected patients of anti-H. pylori Hsp60 antibodies, potentially cross-reactivity between human Hsp60 and a rabbit antiserum against H. pylori Hsp60 suggest that a role of this protein in gastroduodenal diseases is possible.

Amino Acid Sequence↗

p21ras contributes to HIV-1 activation in T-cells.

Activation of T-cells infected by HIV-1 results in activation of long terminal repeat (LTR)-dependent viral transcription and ultimately the production of infectious virus. Although full T-cell activation requires a complex series of intracellular signals, including protein kinase C activation, calcium mobilisation, and less-well defined lymphokine-induced signals, the HIV-1 LTR can be activated by subsets of these signals. We have studied the interaction of these signals in the human lymphoma line, Jurkat, in activation of the HIV-1 LTR. The HIV promoter was induced by IL-1 and phorbol ester activation of PKC but not by a calcium ionophore. The constitutively active form of Ha-ras could replace phorbol ester stimulation of the HIV promoter and of a synthetic promoter containing NF kappa B binding sites.

Enzyme Activation↗

Differential inhibition of IL-1 beta activities and receptor binding by monoclonal antibodies mapping within a discrete region of the protein.

The importance of the region in position 148-192 for the biological activities and receptor-binding capacity of the human IL-1 beta protein has been assessed by the use of mAbs. Four mAbs have been used, which recognize different epitopes within the 148-192 region. None of the mAbs could inhibit binding of IL-1 beta to IL-1RI (expressed on T cells and fibroblasts), suggesting that the 148-192 region does not contain IL-1RI binding sites. Conversely, mAbs Vhp20 (recognizing the fragment 166-169) and BRhD2 (directed to an epitope in the sequence 177-186) recognize sites partially involved in binding to IL-1RII (expressed on B cells, macrophages, and PMN). Only mAbs BRhD2 and FIB 1 (which recognizes an epitope in the sequence 174-186) can inhibit IL-1 beta-induced thymocyte proliferation, whereas all four can inhibit the adjuvant capacity of IL-1 beta in vivo. It is concluded that the region 148-192 encompasses domains important for T cell activation but not for binding to the IL-1RI on T cells, others involved in immunostimulation in vivo, and others important for binding to IL-1RII, although not directly involved in it.

Amino Acid Sequence↗

Induction of gene expression by IL-1 in NIH 3T3 cells. Possible requirement of protein kinase C activity and independence from arachidonic acid metabolism.

NIH 3T3 fibroblasts were transfected with the chloramphenicol-acetyltransferase (CAT) gene under the control of the SV40 early promoter, which can be stimulated by IL-1. CAT activity in cell lysates and PGE2 release in the supernatants were measured in control and stimulated cell cultures in parallel. Human IL-1 beta (180 pM) and human rTNF-alpha (3 nM) significantly stimulated both CAT activity and PGE2 release. The combined incubation of the two cytokines resulted in a synergistic effect on PGE2 release. The addition of AA (30 microM) greatly stimulated PGE2 release without affecting CAT activity. Similarly, drugs interfering with AA metabolism were without effect on CAT activity although profoundly reducing PGE2 release. Forskolin (0.1 microM) did not modify either parameter. The glucocorticoid fluocinolone (20 nM) was able to decrease both parameters. Protein kinase inhibitors H7 (5-50 microM) and sphingosine (50 microM) inhibited only IL-1-induced CAT activity, whereas H8 (5-50 microM) and HA1004 (50 microM) were ineffective on both parameters. PMA (0.5 microM) and R59 022, a diacylglycerol kinase inhibitor (10 microM), did not modify either control or IL-1-induced CAT activity. IL-1-stimulated PGE2 release was potentiated by PMA, although this effect was not inhibited by H7. The data suggest that: 1) in NIH 3T3 cells the activation of AA metabolism by IL-1 is not involved in IL-1-induced gene expression; 2) protein kinase C activity is required but not sufficient for IL-1-induced gene expression; and 3) PMA may stimulate AA metabolism by a mechanism in part independent of protein kinase activity.

Animals↗

A role for protein kinase C activity in interleukin-1 (IL-1) induction of IL-2 gene expression but not in IL-1 signal transduction.

Interleukin-1 (IL-1) is known to synergize with phorbol esters in the induction of interleukin-2 (IL-2) expression in T-lymphoid leukemia cells and proliferation of mouse thymocytes. We used a plasmid construct containing the bacterial gene for chloramphenicol acetyltransferase under the control of the human IL-2 promoter to study the nature of this synergism in the murine thymoma cell line EL4. Although IL-1 induction of the IL-2 promoter in these cells required costimulus with phorbol myristate acetate, the signal induced by IL-1 was qualitatively different. We provide evidence to support the hypothesis that the phorbol ester signal is mediated by protein kinase C, and we show that the IL-1 signal is not. That IL-1 and phorbol myristate acetate represent different stimuli was shown by their response to protein kinase C inhibitors, capacity to synergize with increased intracellular free calcium, and requirement for protein synthesis. In addition we show that pretreatment with IL-1 can prime EL4 cells to subsequent activation by concentrations of phorbol esters not normally sufficient to induce IL-2 expression. Pretreated cells remained primed for at least 40 h after removal of the IL-1. Neither phorbol myristate acetate nor a calcium ionophore was capable of preactivating EL4 cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

Mapping of biologically relevant sites on human IL-1 beta using monoclonal antibodies.

mAb have been raised that recognize human IL-1 beta. Using overlapping peptide fragments expressed in yeast and bacteria, we have mapped the regions of the protein to which these antibodies bind. To assess the relevance of the different regions of IL-1 beta for the expression of its biologic activity, the ability of the antibodies to block IL-1 activity was assayed. Antibodies recognizing the regions 133-148 and 251-269 of human IL-1 beta could inhibit the activity of IL-1 beta, but not of IL-1 alpha, in two different biologic assays, the murine thymocyte proliferation and PGE2 release from human fibroblasts. Conversely, antibodies that recognize the region 218-243 have only a moderate inhibitory effect on the IL-1 beta biologic activity in both assays. Finally, an antibody mapping to the region 148-192 did not inhibit IL-1 beta activity either on thymocytes or on fibroblasts. It is suggested that IL-1 beta-induced cell activation involves different regions of the protein and that both N-terminal and C-terminal fragments are involved in the correct functioning of the IL-1 beta molecule.

Animals↗

The murine interleukin 1 beta gene: structure and evolution.

We have isolated from a genomic library a murine recombinant clone containing the gene coding for interleukin-1 beta m-RNA. A 7000 b.p. DNA fragment has been sequenced. Sequences homologous with human IL-1 beta cDNA have been found distributed within 7 exons. The translation of these sequences allows the prediction of a protein 269 aminoacids long. Hybridization of P388D1 RNA from cells stimulated with phorbol myristic acetate with a genomic DNA probe shows the existence of a 1.6 Kb murine IL-1 beta mRNA which is absent in the unstimulated cells. The comparative analysis between the murine IL-1 beta and the human IL-1 alpha genes shows extreme conservation of the aminoacids at the exon junctions. This observation together with the similarity in number and size of the exons suggests that these genes have diverged from a common ancestor.

Amino Acid Sequence↗

Simple immunization protocol for high frequency production of soluble antigen-specific hybridomas.

We report the immunization protocol used to produce high frequency of specific hybridomas secreting defined antibodies against soluble proteins. The two immunization schemes used consist in 1300 and 115 micrograms of protein distributed over a period of two weeks. The specific efficiency (SE) of positive clones recovered in eleven different fusion experiments ranged between 0.52 and 0.78. These values are referred to hybridomas secreting monoclonal antibodies (MAbs) against soluble proteins such as human chorionic somatomammotropin (hCS), human growth hormone (hGH), and human prostatic acid phosphatase (hPAP). Similar high SE were also recovered by immunizing mice with nonsoluble antigens such as intermediate filaments of cytoskeleton (IF).

Acid Phosphatase↗

[Critical considerations on psychoanalysis, in relation to its possible introduction in the National Health Service].

The Author points out that the psycho-analysis and the psychotherapy of analytical type have been objects of severe criticisms, not always objective and often contradictory. The medical world opposed or ignored at the beginning the Freudian theories and those from them deriving. At present the diffusion of the psychotherapy finds obstacles both in the resistances offered by the medical and social context to which it is addressed, and in the dogmatism and in the scarce flexibility of some psychotherrapeutic schools and currents. Above all the A. focuses on this last aspect, works a review of the shrewdest and most documented criticisms aroused to psycho-analysis and enunciates, lastly, the postulates required in order to have any psychotherapeutic method considered as scientifically trustworthy. This last requisite is indispensable to the introduction of the psychotherapy into the National Health Service.

Attitude of Health Personnel↗